A description of a universal assembler

An "active cell aggregate", or "shape shifter", is an aggregation of similar, space-filling polyhedral machines, preferably built by molecular nanotechnology methods. "Active" means each machine, or "active cell", has the capacity to exchange power and signals with other similar machines, and to interact with the external environment. A robot constructed in this manner can have a very large and detailed envelope of motion. By incorporating simple manipulators onto the various faces of the polyhedron, a universal assembler, or "overtool", may be possible, for molecular, mesoscopic, and macroscopic assembly.